Halo fonts are slightly heavier than the primary font. The spacing and kerning are the same as the primary font. Their purpose is weight management.

Halo fonts can be used to compensate for the weight loss or gain caused by reverse printing, letterpress printing, or any other reproduction process which decreases or increases the weight of the type. Using the weight just above or below the one currently selected will add or subtract a just-noticable increase or decrease.